Did you clean and adjust the limit switch on the replay unit? That is the switch that opens when the unit is at the maximum number of credits. If this switch is dirty/out of adjustment, you will get the symptom you describe.

Be sure to check for a detached wire at the switch solder lugs when adjusting the limit switch. And it's always a good idea to tighten down the switch stack screws before making adjustments to switch blades.

- TimMe

I think it's a good strategy to confirm each of your assumptions and trouble-shoot one step at a time.

For example, how do you know the replay unit ADD coil is good? What happens when you briefly connect a jumper wire from the 25 VAC fuse block to the (non-black) solder lug of the replay unit ADD coil? Does the coil fire and step up the replay unit?

- TimMe

OK, If you were able to actually step up the replay unit with a 9 V battery, that's great.

The replay add circuits on Roller Coaster are the usual GTB circuitry - nothing tricky going on. Assuming you've got PF power during normal game play, then the replay pulse for high score goes through these circuit elements (in this order):

- An N.O. switch on the L (100 pt) relay.
- A P1B make/break switch on the player unit.
- 1st/2nd player hundreds score unit disc and wiper.
- The various plugs and the high-score selector socket the head.
- 1st/2nd player thousands score unit disc and wiper.
- A P1A make/break switch on the player unit.
- The high-limit (AKA "15th position") switch on the replay unit.

If your game is not awarding replays for high scores, and you've already confirmed that the replay limit switch is not the issue, then I would check each of these for a circuit fault of some kind.

For what it's worth, one strategy is to start at the last item (the high-limit switch) and work your way backward through the list. You can use a jumper wire from the 25 VAC fuse block to briefly put power on each of these items. Each time you do that, the replay unit should step up. As you go back through the circuit, at some point the replay unit will stop stepping, and then you'll know the general area of your circuit fault.

If you do use the jumper technique, remember to keep knocking credits off the replay unit by hand, because it will stop working if you let it step all the way up to the max credit position!

- TimMe